At the National Land Survey of Finland, a new QGIS-based topographic data production system was introduced last year. The system includes quality assurance tools that enable users to verify the logical consistency of topographic data.

The tools support validation of attribute value domains, geometric consistency, and the correctness of topological relationships among maintained features. Detected quality errors are listed in a QGIS panel and visualized in the map view.

To assess topological consistency, nearly 20 different topological rules have been defined. The rules are applied to relevant pairs formed from approximately 100 different feature classes (points, lines, and polygons), resulting in about 8,000 distinct rule evaluations. Quality checks are performed directly in the PostGIS database whenever edits made in QGIS are saved, and the results are presented to users almost in real time.

In this presentation, I will introduce the operating principles of the quality assurance tool, the adopted custom-made topological rule set, and demonstrate how these rules support the maintenance of topographic data.